test262/test/built-ins/Proxy/defineProperty/trap-is-undefined-target-is...

56 lines
1.4 KiB
JavaScript

// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc
description: >
If "defineProperty" trap is null or undefined, [[DefineOwnProperty]] call
is properly forwarded to [[ProxyTarget]] (which is also a Proxy object).
info: |
[[DefineOwnProperty]] (P, Desc)
[...]
5. Let target be O.[[ProxyTarget]].
6. Let trap be ? GetMethod(handler, "defineProperty").
7. If trap is undefined, then
a. Return ? target.[[DefineOwnProperty]](P, Desc).
features: [Proxy, Reflect]
includes: [compareArray.js]
---*/
var array = [];
var arrayTarget = new Proxy(array, {});
var arrayProxy = new Proxy(arrayTarget, {
defineProperty: undefined,
});
Object.defineProperty(arrayProxy, "0", {value: 1});
assert.compareArray(array, [1]);
assert.throws(TypeError, function() {
Object.defineProperty(arrayProxy, "length", {
get: function() {},
});
});
var trapCalls = 0;
var target = new Proxy({}, {
defineProperty: function(_target, key) {
trapCalls++;
return key === "foo";
},
});
var proxy = new Proxy(target, {
defineProperty: undefined,
});
assert(Reflect.defineProperty(proxy, "foo", {}));
assert.sameValue(trapCalls, 1);
assert.throws(TypeError, function() {
Object.defineProperty(proxy, "bar", {});
});
assert.sameValue(trapCalls, 2);